Because the return type is optional, it needs to be unwrapped before you can use it.
But be careful, it may not have a value (i.e. it may be equal to nil) and unwrapping nil values leads to runtime crashes.

So you need to check for that before you can use the returned string:

if let returnedString = result {
println("the result is \(returnedString)")
}

This means: If result is not nil then unwrap it and assign it to a new constant called returnedString.